Boiler Fault Code Room Thermostat Fault

Also written as ROOMTHERMOSTATFAULT — same fault.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026

Fault code Room Thermostat Fault appears across 1 boiler brand and 5 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.

Most common meaning Your boiler has lost communication with your heating controls, meaning your radiators might not turn on when you want them to. (As reported on Ideal Logic Code Combi ESP1)